The Schönenwerder collegiate church is located in Niederamt east of Olten and is the oldest significant and more or less unchanged preserved medieval building in the canton of Solothurn (which incidentally, with the exception of some castles such as Alt-Falkenstein and the crooked tower in the capital almost only fragmentary has medieval buildings). It was built for the most part between 1025 and 1050, ie in the historical era of the early Middle Ages. The Canon monastery St. Leodegar in turn was founded in the 8th century and dissolved in 1874 as a result of the Kulturkampf [2].
The oldest parts of the collegiate church are still from the original building from the 11th century. In 1388, the church was burnt out and rebuilt in 1491. A cloister has been added to the south wall of the church since 1610, for which grave slabs have been reused as building material. Due to the steeply falling Bühlfelsens the cloister is not square, but rectangular. The original two Late Gothic towers had to be demolished in the 17th century, instead 1676-1679 the existing front tower was built. Stiftspropst Leonz Gugger donated the glorious high altar with Our Lady in the Radiant Wreath in 1759 and began building the Rococo-style church. The altar of Mary on the gallery and two other altars are from this period.
Since 1876, the Christian Catholic community of Schönenwerd with the approval of the Solothurn government held their services in the collegiate church. Today it belongs to the Christian Catholic parish. [4] The Protestant-Reformed parish has a shared right and performs in the collegiate church regularly through their worship.